We are continuing to investigate the noisey valve train on the spyder. It looks like is is from number 3 inlet valve. All spark plugs fine. ECU says no 2 and 3 missfire. Having taken the cover off, nothings obviously damaged or worn. Cable to variable timing motor has split letting oil into the cable. Are there any home check that can be performed on these units? Grateful for any ideas.
4200 noisey valve train
- Thread starter rotor-g
- Start date
We have conducted a compression test and leakdown test. No 3 cylinder has NO compression!! An endoscope shows some detonation on the piston, but still a little confused. We think it may be detonation caused by ingesting oil caused by a blocked air filter. If we are to rebuild the engine, does anyone know if the bores have Nicoseal and can you get over sized pistons? Is there any advice on removing and rebuilding these engines?
BennyD
Sea Urchin Pate
- Messages
- 15,006
Crikey, that doesn't sound good. If that's the case I won't be sticking an endoscope in mine any time soon. My piston tops will be like a teenagers face and my valves will be like bananas due to chronic, and repeated, over revving. However, at the moment she seems to be running like a Swiss watch and I'll keep thrashing her until she doesn't! I guess life just isn't fair.
Anyhoo, back to the conversation; if it's only the piston top that kn4ckered, just replace that with a used standard piston if the bores aren't damaged. Is the piston top holed or is there valve damage? Has the piston-top damage been caused by valve interference? Also, if the air filter is blocked I would look at whoever last serviced it as it takes an awful lot of debris to block it to that extent and I would suggest it hasn't been changed for a long, long time. Good luck to you for a swift, and inexpensive, return to robust health.
Anyhoo, back to the conversation; if it's only the piston top that kn4ckered, just replace that with a used standard piston if the bores aren't damaged. Is the piston top holed or is there valve damage? Has the piston-top damage been caused by valve interference? Also, if the air filter is blocked I would look at whoever last serviced it as it takes an awful lot of debris to block it to that extent and I would suggest it hasn't been changed for a long, long time. Good luck to you for a swift, and inexpensive, return to robust health.